Adjustable beds are commonly used in hospitals as well as homes, generally for persons who must spend a great deal of time in the bed. Such beds often have multiple sections that may be adjusted in angular relation to one another so as to maximize the comfort of the user. A conventional mattress does not function properly when used in conjunction with one of these adjustable beds because the mattress is not intended to bend. The generally rectangular upper and lower border wires of a conventional mattress are rigid and not intended to be bent. Therefore, a conventional mattress is not suited to be used in conjunction with an articulated bed.
Mattresses have been designed and constructed which have multiple sections hingedly connected to each other in order to be used with adjustable beds. Such mattresses allow the contour of the mattress to fit the position in which the user places the adjustable bed. One such mattress is disclosed in U.S. Pat. No. 3,419,920. However, the different portions of this mattress are not made up of aligned coil springs but rather are made of polyurethane foam. The mattress disclosed in this patent has multiple hinges allowing one section of the mattress to move independently of the other sections.
Another patent which discloses an articulated mattress to be used in conjunction with an adjustable hospital bed is U.S. Pat. No. 5,214,809. This patent discloses an articulated innerspring mattress comprising four rigid spring core sections, each section being placed within a pocket of fabric. The pockets of fabric are hingedly connected to each other with a transversely extending hinge portion made from the fabric. The hinges enable the mattress to bend along transversely extending joints and the sections of spring core to be angularly inclined relative to each other. Above and below the transversely extending hinge are foam bars glued to the fabric hinge. The foam acts as a filler material and prevents the bunching of the fabric surrounding the rigid spring core sections. The four pockets are covered with a mattress pad and enclosed in a cover so as to complete the articulated mattress. The difficulty with this type of mattress construction is that the individual spring core sections must be pocketed increasing the cost of manufacturing the spring assembly and the amount of material necessary to construct the mattress. In addition, two pieces of resilient foam must be placed in each hinge and the foam adhesively secured to the fabric of the pockets and hinge. This increases the time and expense required to manufacture the mattress.
Another patent which discloses sections of a mattress which are bendable or foldable relative to one another is German Patent No. 2827821. This patent discloses a mattress having two sections of spring core connected to each other at a bendable joint. Layers of upholstery cover the top and bottom surfaces of the mattress. The end turns of the coil springs are embedded in layers of foam or adhesive which secures these coil springs to the upholstery layers. The upholstery is what actually connects the different sections of spring core to each other. Difficulties with this type of construction are that 1) foam or adhesive must be injected through the upholstery with hollow needles in order to secure the coil springs in place and 2) the end turns of the coil springs adjacent the hinge must be embedded in the adhesive or foam. This increases the time and costs of manufacturing the mattress. In addition, should a great deal of stress be placed on one coil spring section relative to the other, the end turns embedded in the foam or adhesive may rip or tear away from the foam or adhesive destroying the relationship between the sections of spring core.
Therefore, it has been one objective of the present invention to provide an articulated mattress in which multiple sections of spring core are hingedly connected to each other in a more secure manner than heretofore known articulated mattresses.
It further has been an objective of the present invention to provide an articulated mattress having foam hinges connecting multiple sections of spring core to each other.
It further has been an objective of the present invention to provide an articulated mattress in which the sections of spring core are fastened to a foam hinge with fasteners rather than end turns of coil springs being embedded in the foam.